Shock absorbers are intended for developing forces providing the elimination or reduction of the amplitude of cars or their parts fluctuations. On the CIS railroads, the wedge-type shock absorber became the most wide-spread in trucks of freight cars. In friction shock absorbers, the friction force arises in vertical and horizontal movements of the absorber wedges rubbing on friction plates fixed on the columns of the truck sidewalls. In the article, the modeling of dynamic characteristics of a freight car with the optimized parameters of the wedge-type shock absorber is performed. The modeling is performed by means of the software complex for studying the problems of dynamics of rail vehicles: “The universal mechanism”. A dynamic and block diagram of the dynamic model of the car platform, as well as of the mathematical model for studying the friction force and interaction of contact power elements, accounting the creep forces in contact by means of the FASTSIM algorithm based on the Kalker linear theory, is developed. The obtained results of modeling of an eight-wheel freight car with modernized frictional wedges show that in the truck modernization it is expedient to provide additional devices, for example a frictional shock absorber in the central step of suspension. The results of the carried out study prove the expediency of using for the upgraded truck of 18-100 model the design of M1816.06.000 SB, M1819.00.000 SB wedges, at this it is recommended to accept rigidity of elastic elements of these wedges equal to 1.1 kN/mm that is a compromise solution for the safe car movement in the empty and loaded modes.

The research aims to determine the optimal modes of hardfacing when restoring the shafts of electric motors, taking into account the resulting hardness of the deposited layer for further machining. When conducting a full-scale experiment on hardfacin...

Some results of measurements of bending deformation concrete span bridge are given. It is shown that for a more detailed estimation of the dynamic answer of the structure and the establishment of the correspondence between the analytical model and behavior of structure, it is necessary to carry out periodic monitoring of tense-strained state of the structure under operating load.

This work is devoted to the analysis of the stress-strain state of the surfaced gear teeth using the T-Flex CAD software. The study showed that the surfaced teeth are able to withstand workloads, as well as loads increased by 50%, demonstrating a deformation of only 2%. Zones of maximum stresses and deformations have been identified, which makes it possible to predict the durability and reliability of the surfaced teeth. The conducted studies confirm the effectiveness of the electroslag surfacing method for restoring gears and its application to improve the performance of gears under high loads.

The article focuses on the results of a study of the effect of electroslag surfacing modes on the penetration depth of restored teeth, conducted on the basis of a full factorial experiment (FFE) type 22. The welding current and the voltage on the slag bath were selected as factors. Each experiment was repeated three times, and the results were analyzed to build a regression model that takes into account all interactions of factors. The article describes in detail the process of encoding variable factors, constructing a planning matrix, calculating the coefficients of the regression equation and checking them for significance using the Student’s criterion. The adequacy of the experiment was confirmed by calculations using the Fisher criterion (Fcalculated<Ftable). According to the results of the experiment, it was found that the stress on the slag bath has the most significant effect on the total depth of penetration. The optimal mode has been determined (welding current 400 A and voltage on the slag bath 45 V), which provides the required penetration depth (4.63 mm) of a large-modulus tooth. The convergence of the results of the full-scale test with the results of planning a full factor experiment of type 22 was revealed, which made it possible to determine the optimal surfacing mode. This study can be used to optimize the parameters of electroslag surfacing, which will lead to an increase in the quality and efficiency of restoration of worn teeth. Keywords: electroslag surfacing, surfacing mode, penetration depth, welding current, welded tooth.

This paper presents the development of a digital model of the production process at a mechanical engineering enterprise, aimed at improving management efficiency using Big Data technologies and multi-criteria optimization methods. The structure of a machine shop was formalized, identifying the main functional elements of the production system, including production areas, buffers, product flow routes, and intra-shop logistics. Parametric models of production units were developed, enabling the assessment of throughput, equipment utilization, work-in-progress volumes, and operating costs. The study analyzed the influence of machining process parameters on surface quality indicators. Predictive dependences of machining quality on cutting speed, feed rate, vibration level, spindle power, and tool wear were constructed. Three-dimensional models of surface roughness variations and heat maps of equipment utilization were developed, enabling the identification of bottlenecks in the production process. An intelligent methodology for optimizing a production system is proposed, based on machine learning, multi-criteria analysis, and digital modeling. The obtained results confirm the possibility of applying the developed approach to creating digital twins of production processes and improving the management efficiency of mechanical engineering enterprises